Boiler-furnace.



M. W. SEWALL.

2 SHEETS-SHEET 2.

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Patented Apr. 20, 1915.

M. W. SEWALL.

BOILER FURNACE.

APPLICATION FILED NOV. 26, 19,12.

2 SHEETS-SHEET l.

WITNESSES" M Arm/MEN,

rangements MINOTT W. SEWALL, OF NEW COMPANY, OF BAYONNE,

YORK, n. Y., assrenon TO THE BABCOCK & wrncox new Jersey, A conrona'rronon NEW JERSEY.

BOILER-FURNACE.

aser 72 5. Original application filed May 27, 1912,

To all whom it may concern Be it known that I, MINOTT a citizen of theUnited States, residing at New York city, borough of Manhattan, in thecounty of New York and State of New York, have invented certain new anduseful Improvements in Boiler-Furnaces, of which the following is aSpecification.

The present application is a division of my application, Serial No.699,800, filed May 27, 1912 upon which Patent No. 1,06-l,175 has beengranted dated June 10, 1013'. In that application I have describedcertain improvements upon the furnace constructions shown in my PatentsNos. 983,000 and 983,170 granted January 31, 1911. In the construct-ionsshown in said patents the greater part of the dust that passes over fromthe furnace naturally falls to the floor behind the bridge wall. Itisthere subjected to the reflection of the heat and becomes fused into asolid mass on the floor of the it. This mass is very dillicult toremove, as when cold it is a solid mass of clinker. 11? the pit is madeof sullicient depth, so that the temperature at the bottom is notSullicient to fuse the dust, the latter may be ,easily removed. If,however, it is allowed the top of the bridge to build up too nearbecomes fused and wall, the surface of it becomes a solid mass as beforementioned. This is a real diiliculty, and one that isnot easily overcomewithout considerable expense in construction and attention in operation.

Several arrangements have been used by different makers of chain gratesto cover the rear end of. the grate and.at the same time to pass anyunburned carbon over the covering parts and discharge them behind thegrate on either an auxiliary dumping grate or a dumping plate. Some ofthese arrangements have been made in the form of a hollow casting whichcovers the top of the rear of the grate and is formed with a slopetoward the front of the grate so as to permit the unburned carbon topass over it easily. This casting was filled with water so as to preventits burning out. Other arbave been made having solid covering plates orbars tapered toward the front. These havebeen made of various grades ofiron and steel, the efiorts having Specification of Letters Patent.

TV. SEWALL,

Patented Apr. 20, 1915.

Serial No. 699,860. Divided and this application filed November 26,

1912. Serial No. 733,584.

burned carbon from passing over has led.

to the adoption of a water back, such as shown in my Patent No. 9-l1,557granted November 1000. A brick bridge wall is also sometimes used tocompact the ash and permit the fire to pass under. This is, however, avery inellicient arrangement. Either the water back as mentioned or thebrick construction permits a certain amount of unburned carbon to passover the rear of the grate, which carbon falls into the ashpit. If theashpit is not cleaned at proper intervals the carbon and ash fill thepit and burn, and such a temperature is produced that the rear of thegrate is heated to a detrimental degree. In order to prevent thisheating, .1 have designed a stripper to be used in combination with awater bridge wall, or with a brick bridge wall, as mentioned. Thisstripper extends from approximately the tangent point otthc rear curveof the grate downwardly and causes any ash or unburned carbon to passover it into a pit behind the grate and does not permit the ash to passinto the space under the grate. The pit be hind the grate may be simplyan ashpit or it may contain a grate on which the ash and unburned carbonmay fall and remain there until the carbon is burned out, the ash beingremoved periodically. In said Patent No. 941,057, a rectangular box ISshown. The

of al- 0 The invention will be understood by'reference to theaccompanying drawings, in which" Figure 1'is a vertical longitudinalsection Fig- 2, a sectional plan view on the plane of line 22 of Fig. 1athe left-hand portion oi Fig. 3, a. vertical cross-section on the planeof the line 3-3 of Fig. 1, the right-hand 1- 1s a View of an enlargedportion ,of they Referring to the drawings, the numeral 1 designates theboilercasing, in the upper part of which are located. the heatingsurfaces and other parts ofa boiler not here shown. have described thesidetubes 2 and their connection With the' water circulation through themanifolds 8 and 4. At the rear of the traveling grate 5 is a Water box6, and extending along both side walls approximately at the grate level,are water boxes 7.. A second cross box 8 is placed above the box 6, andthese two boxes form ,the bridge wall of the furnace. The water supplyfor thls box system is from the rear manifolds 3 through tubes 9, theforward ends o't said tubes entering the under side of boxli near itsends. Box 8 receives its Water supply from box 6 through nipples 10 nearthe center of said boxes. The side boxes 7 receive their supply from box0 through nipples 11, and'their Water discharge is through two pipes 12at their forward or elevated end, into a box, not shown. Box 8 has itsdischarge through pipes 13 into the front manifolds t, and also throughpipes 15 into a box, not shown.

immediately to the rear of box 6, and extending toward the mud drum 16 lhave introduced av screcn'of water tubes 17. This screen extends acrossthe furnace, the ends of the tubes 17 being expanded into the manifolds1S and 1f), the latter being at a higher level than the former in orderto give an inclination to the tubes 17. ,The water supply to n'ianit'old1S enters from one of the manifolds 3 through nipple 20, the circulationpassing through tubes 17 into manifold 19, and from the latter into box8 through a nipple 21.

it will be seen that I have modified the Furnace ol my said Patent No.983,000 by introducing a screen of water tubes behind the bridge wall,which will largely prevent the rrllection ot' the heat from the combustonchamber downwardinto the pit behind the bridge wall.

For the purpose of passing theash and fuel refuse over the rear end ofthe grate 51 I provide a shield or stripper extending preferably fromapproximately the rear edge ottho water box 0, 0' approximately thetangent point of the curve of the grate. It is, however, not absolutelyessential that this shield sln'iuld reach as high on the grate as abovestated, as a partial protection of the grate may be secured by havingthe upper edge ol the shield as low, or perhaps lower, than the centerof the sprocket shaft,

In my said Patent No. 1,064,175 I one purpose of the shield being toconduct the ash and fuel. refuse which pass under the bridgewall overthe top of the shield may froin thc grate -and thus to preterit hot orburning material being discharged underuthe grate.

llonthe purpose of cll'ecting complete combustion of any umronsuincdcarbon. which may be dischargml over the rear of the grate, I provide anauxiliary furnace having'a grate or floor 1.3, one. of the side walls ofthis furnace chamber providing a convenient means to which the shield orstripper may bo'sccurcd, as shown in Fig 1. The products of combustionfrom this auxiliary tturnace pass directly up between the tubes 1? andmingle with the products oil combustion fr m the lurnaco proper. An ashreceiver 2-1 will receive the ash from the auxiliary furnace, saidreceiver being made air-tight with a. controllable air entrance E25. A.rcceirer 26 below the traveling grate receives any tine coal that maylcal; through the grate. This means of disposing of the ash and fuel roluse prevents the hunting ol' the rear of the tin-ivcling grate andthereby obviates the objections before noted.

What .l: claim and desire to secure by Letters Patent oi the llnitedStates is:----

l. A'boiler l'urnacc having a traveling grate, a bridge wall above thegrate at the rear, a shield in proximity to the roar cnrvaruro oi thegrate, a pit for the ash and. tool refuse which discharged between thegrate and the bridge wall over said shield, anua series of water tubesi'orininn; a shield for said pit for the purpose dosrrilrwl.

2. boiler furnace having a grate, a pit at the rr-ar oil' the grate,means for discharging the ash and 'rlllfl refuse from the grate intosaid pit. and a series oi" \valor tubes forming a shield over said pitfor tho pnrpose drscribcd.

53. A boiler furnace having a grate, a pit at the rear of the gratebelow the rear of the furnace comlnrstionrhamlm. means For causing theash and tool refuse to discharge From the grate into said pit, and aseries of water tubes forming a shield over said pit said tubes beingronncrlml circulation.

l. .l. boiler furnace having a grate, a bridge wall, a pit at the roar fthe grate, means for causing the ash and l'ucl rolusc to pass und. -.rthe bridge wall and beyond 3 with the boiler the grate into said pit,and a series of water tubes Forming a screen above said pit For thepurpose (loser-died.

' 5. A boiler furnace having a traveling grate, a water-box bridge wallabove the grate at the rear, a shield or stripper cxtending from therear curve of the grate downwardly, a pit beyond the grate for tho ashand fuel rcluse discharged between the grate and bridge wall over saidshield, a, signed my name in the presence of two subwull sepurutlng [beplt from the space bescrlblng \vltnesses.

neuth the grate. means for supporting the x 1 r r 1 ilIk Fl SEWALL.unburned tuel J11 tne plt, and a heat-ubsorb- 0 mg n'xelnber lucuwlbetween the plt and Nltnessesz steam generator. M. 1). McNlxol-l,

in testimony \vlureof I have hereunto CHARLES S. JONES.

